It Gets Better
http://www.itgetsbetter.org/

The Trevor Project
If you're considering suicide, call 866-4-U-TREVOR (866-488-7386) right now. There are people standing by ready to talk to you.
http://www.thetrevorproject.org/

Gay-Straight Alliance Network
http://www.gsanetwork.org/

We DO Campaign
http://southernequality.org/